Electrostatic spinning head funnel

ABSTRACT

An open end electrostatic spinning head apparatus for textile fibers having stationary housing with a throughbore therein; a hollow spindle means rotatably mounted in said housing, the spindle means further comprising a fiber-collecting funnel at the upper end of the spindle means whereby a narrow space bounded by the outer wall of said funnel and said housing throughbore is defined, this funnel having a dielectric shank portion attached to the upper end of the spindle means and electrode means mounted within said housing for electrostatically attracting charged fibers to said collecting funnel. A conductive sleeve means is mounted to and covers the outer surface of the shank portion whereby stray charged fibers entering said space reverse their charge and are repelled from said electrode means upon coming in contact with the conductive sleeve means.

[451 June 20, 1972 ABSTRACT 2 Claims, 2 Drawing figures An open endelectrostatic spinning head apparatus for textile fibers havingstationary housing with a throughbore therein; a hollow spindle meansrotatably mounted in said housing, the spindle means further comprisinga fiber-collecting funnel at the upper end of the spindle means wherebya narrow space bounded by the outer wall of said funnel and said housingthroughbore is defined, this funnel having a dielectric shank portionattached to the upper end of the spindle means and electrode meansmounted within said housing for electrostati- 57/106 cally attractingcharged fibers to said collecting funnel. A con- Dolh 1/12 ductivesleeve means is mounted to and covers the outer sur- 575889-5895 face ofthe shank portion whereby stray charged fibers entermg said spacereverse their charge and are repelled from said electrode means uponcoming in contact with the conductive sleeve means.

POWER SUPPLY FUNNEL [72] Inventor: George L. Murray, Jr., Milford, Mass.

North American Rockwell Corporation, Pittsburgh, Pa.

Dec. 9, 1970 [21] App]. No.: 96,402

References Cited UNITED STATES PATENTS 1/1971Chabot................................

United States Patent Murray, Jr.

[54] ELECTROSTATIC SPINNING HEAD [73] Assignee:

[22] Filed:

[58] Field of Primary ExaminerJohn Petrakes I Attorney-John R. Bronaugh,Floyd S. Levison, E. Dennis O- Connor and Richard A. Speer POWER SUPPLYELECTROSTATIC SPINNING HEAD FUNNEL BACKGROUND OF THE INVENTION Field ofthe Invention This invention relates to an improved spinning head funnelapparatus for the performance of open end electrostatic spinning oftextile fibers into yarn. Normally electrically charged fibers areattracted to an oppositely charged rotating funnel throat of a hollowspindle means. However, some fibers do not follow the normal path intothe rotating funnel throat but instead stray into a narrow space definedby a narrowing funnel throughbore opening in a stationary housing in theouter wall of the funnel. These stray charged fibers are attracted tothe outer wall of the rotating funnel and have a tendency to seep downthe spindle bore hole of the spinning head housing and consequently jamthe bearings journalling the hollow spindle. These fibers sometimesadhere to the funnel shank causing a buildup of fibers which may:disrupt the spinning process by windmilling; reduce the rotational speedof the funnel by friction; or cause abrasive damage to the plastichousing or funnel. The fibers sometimes become matted and begin to burndue to frictional heat generated by the fibers being trapped between therotating funnel wall and the spindle bore wall of the stationaryhousing. Expensive down time is incurred due to the fact that thespinning process must periodically be interrupted in order to clean outsuch stray fiber accumulations.

It is the principal object of this invention to provide an improvedelectrostatic spinning head funnel construction which causes straycharged fibers coming in contact with the funnel shank to quicklyreverse charge and be repelled from an electrode mounted adjacent thefunnel.

It is a further object of the invention to provide a smooth surfacedfunnel shank so that stray fibers are not caught by scratches orabrasion marks on the shank. A smooth surfaced funnel shank further aidscentrifugal forces of rotation in throwing off stray fibers.

SUMMARY OF THE INVENTION This invention provides an improvedelectrostatic spinning head funnel having a smooth metal sleeve mountedto and covering the shank of the rotating dielectric funnel. The smoothmetal sleeve enables any charged fibers coming in contact with it toquickly reverse charge and be repelled from an electrode mountedadjacent the funnel, thereby maintaining internal rotating parts of thespinning head free of extraneous fiber debris.

BRIEF DESCRIPTION OF THE DRAWING Other features of the invention willbecome apparent from the following more detailed description and fromthe accompanying drawing, in which:

FIG. 1 is a sectional view of the funnel and conductive sleeve of thefunnel shank;

FIG. 2 is a side elevational view in partial section showing theconductive sleeve in cooperation with a rotating funnel mounted in anelectrostatic spindle system.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the Figures,the fiber receives an electrical charge from rolls 12 connected to asource of potential as the fiber exits from the feed system. The fiberis attracted to a spinning head assembly 14 which includes a normallystationary body 16 and end caps 18 and 20 mounted respectively on theupper and lower ends of the body 16.

A twisting device including a spindle 22 is journalled in the body 16 byaxially spaced aligned anti-friction bearings 24 and 26 fixed within thecentral throughbore 28 of the body 16. Body 16 has laterally extendingside openings 30 to the enlarged central portion 32 of the spindle 22which is frictionally driven by an endless belt 34 extending throughopening 30 and continuously rotated by a drive portion of the spinningapparatus (not shown).

Spindle 22 has an axial throughbore 36, the lower end of which defines ayarn discharge opening 38 from which spun yarn (not shown) is drawn bytakeup or drawing rolls 40 and 42.

The upper end of the spindle is counterbored at 44 to receive a gripper46 into which fibers (not shown) are directed to be twisted and spuninto yarn. Gripper 46 may, of course, be one of the types illustrated inU.S. Pat. No. 3,372,537, issued Mar. 12, 1968 to M. Poul] et al. for"Radially Clamping Grips."

The upper end of the spindle 22 has an extension or funnel 48 defining aconical fiber inlet opening. This extension is made of a dielectricmaterial and is positioned for rotation within a centrally disposedthrough opening 50 in the cap 18. Extension 48 has an aperture 49terminating in a cylindrical opening 51 in axial alignment with andsubstantially equal in diameter to the inlet end of the gripper 46. Theyarn tail extends through opening 51 from gripper 46 into the aperture49 and attracts fibers from rolls 12 which are presented to the yarntail as it rotates to the maximum field where the tail is maintained.

The annular metallic negative electrode, or cathode 52 of theelectrostatic system is fixed within the body 16 of the spinning head 14in axially aligned surrounding relation to the spindle 22 below the cap18. Electrode 52 is connected by a lead 54 to a terminal of high voltageelectrostatic power supply, the other terminal of which is grounded. Theupper external surface of electrode 52 is a segment of a sphere formaximum field focusing strength. A configuration of the electrotaticfield is represented by dotted lines 56 as it extends from the upperdielectric surface of the cap 18 to the metallic portions of the rolls12 which provide a ground for the electrostatic field.

In operation fibers entering the electrostatic field are given a chargeby passing over the rotating rollers 12. A few of these charged fibersstray from the normal path of flow into the twisting device 22 locatedwithin the spinning head 14. Some of these stray fibers are evacuatedfrom this area through a hole 62 by means of a suction tube 60 whichextends into the side of cap 18. Suction tube 60 being connected to anair evacuation device (not shown).

Rotating funnel 48 has a shank portion 64 which engages and fits overthe upper end of the spindle 22. A smooth metallic sleeve 66 is mountedon and covers shank portion 64. This conductive sleeve controls fiberbuildup because the charged fibers coming .in contact with the sleevequickly reverse charge and are repelled from the area of the oppositelycharged electrode 52. The smooth surface of the metallic sleeve will notcatch fibers as readily as the scratched or abraded plastic surface.Finally, although a nep or slub of fibers may find itself trapped inthis region for some time before being evacuated, it slides easily onthe metal sleeve and does not damage the sleeve by abrasion.

It is to be understood that the above detailed description of thepresent invention is intended to disclose an embodiment thereof to thoseskilled in the art, but that the invention is not to be construed aslimited in its application to the details of construction andarrangement of parts illustrated in the accompanying drawings, since theinvention is capable of being practiced and carried out in various wayswithout departing from the spirit of the invention. The language used inthe specification relating to the operation and function of the elementsof the invention is employed for purposes of description and not oflimitation, and it is not intended to limit the scope of the followingclaims beyond the requirements of the prior art.

What is claimed is:

1. An improved spinning head funnel for use with spinning head apparatusused to perform open end' electrostatic spinning of yarn fibers intothread wherein internal rotating parts are maintained free of extraneousfiber buildup comprising:

a. a stationary housing having a throughbore therein;

b. a hollow spindle means rotatably mounted in said housc. drive meanswithin said housing for rotating said spindle nel; and

g. a conductive sleeve means mounted on and covering only Sald sPlndlemeans R f a dlelecmc fiber the outer surface of said shank portion ofsaid funnel collecting funnel extension constituting the upper end ofwhereby stray charged fiber entering said space reverse the spmdle meansPY a space 5 their charge and are repelled from said electrode means theouter wall of said funnel and said housing upon coming in Contact withsaid conductive sleeve throughbore is defined; means e. said funnelhaving a dielectric shank portion mounted over the upper end of saidspindle means;

f. electrode means mounted within said housing for electrostaticallyattracting charged fibers to said collecting fun- 2. The apparatus asdefined in claim 1 wherein said conductive sleeve means is smoothsurfaced.

l l i Dedication 3,670,486.Geo1"ge L. Mummy, Jra, Milford, Mass.ELECTROSTATIC SPIN- NING HEAD FUNNEL. Patent dated June 20, 197 2.Dedication filed Mar. 23, 1977 by the assignee, Electwospz'nOarpomtz'on. Hereby dedicates to the Public the entire term of saidpatent.

[Ofitcz'al Gazette May 10, 1977.]

1. An improved spinning head funnel for use with spinning head apparatusused to perform open end electrostatic spinning of yarn fibers intothread wherein internal rotating parts are maintained free of extraneousfiber buildup comprising: a. a stationary housing having a throughboretherein; b. a hollow spindle means rotatably mounted in said housing; c.drive means within said housing for rotating said spindle means; d. saidspindle means further comprising a dielectric fiber collecting funnelextension constituting the upper end of the spindle means whereby anarrow space bounded by the outer wall of said funnel and said housingthroughbore is defined; e. said funnel having a dielectric shank portionmounted over the upper end of said spindle means; f. electrode meansmounted within said housing for electrostatically attracting chargedfibers to said collecting funnel; and g. a conductive sleeve meansmounted on and covering only the outer surface of said shank portion ofsaid funnel whereby stray charged fibers entering said space reversetheir charge and are repelled from said electrode means upon coming incontact with said conductive sleeve means.
 2. The apparatus as definedin claim 1 wherein said conductive sleeve means is smooth surfaced.